DE10038144B4 - Vehicle automatic transmission with fault detection device - Google Patents

Abstract

Vehicle automatic transmission with:
a plurality of shift elements (L / C, 2-4 / B, H / C, L & R / B, R / C) of a gear shift mechanism in which combinations of engagement states of the respective shift elements (L / C, 2-4 / B, H / C, L & R / B, R / C) are selected by means of a hydraulic control section (24) to perform multi-speed shifting, and
hydraulic switching means (25-28) provided in the hydraulic control portion (24) for preventing the gear shift mechanism from becoming locked;
marked by
an error detecting device (101-113) that detects occurrence of a failure of said hydraulic switching device (25-28), said error detecting device (101-113) comprising:
a gear determination device (101) to determine the current gear of the automatic transmission,
an error detection start determination means (102-106) which determines the start of fault detection of the hydraulic shift means (25-28) in accordance with the determination result of the gear determination means (101),
a memory for storing the switching elements selected for the combinations of engagement states for the respective gears and the shift elements not selected for the respective gears in the form of a table,
a...

Description

The The present invention relates to a vehicle automatic transmission according to the generic term of claim 1

The JP 08-121586 from May 14, 1996 indicates a hydraulic control device for a vehicle automatic transmission with electronically controlled switching pressure.

at the vehicle automatic transmission indicated in the above-mentioned patent publication is as a fail-safe valve for an LR brake (LR: Slow / Reverse), the is engaged when the first gear of the D range (D: forward drive) is selected, and the solved is selected when the second, third or fourth gear of the D range is selected, a structure for forced draining of the hydraulic pressure provided the discharge of hydraulic pressure applied to the LR brake enforces when the gear is the second, third or fourth gear of the D range is where the hydraulic pressure with either a second Brake pressure P2ND or an overdrive clutch pressure POD generated is, wherein the second brake pressure P2ND, the hydraulic pressure for a second Brake is coupled in the second or fourth gear of the D-range and wherein the overdrive clutch pressure POD is the hydraulic pressure for one Overdrive clutch is the third or fourth gear of the D range is coupled.

at this hydraulic control device for the vehicle automatic transmission however, no determination facility is provided to establish whether a first coil, the structure for the forced release of the Hydraulic pressure forms, is blocked (or inhibited). If the first Coil is blocked at a position where the overdrive clutch pressure POD would enter connected to the LR brake and then because of the inhibition of the first coil be locked if an abnormality in a hydraulic system occurs under the LR brake pressure and an undesirable hydraulic pressure is generated.

A corresponding to the preamble of claim 1, from the US 5,836,845 A The known automatic transmission includes a plurality of switching elements that are controlled by a hydraulic control unit to perform a shift between different gears. Two fail-safe valves serve to prevent blocking of the switching elements.

From the DE 3 843 101 A1 For example, there is known an automatic transmission type error detecting apparatus having a multiple-speed shifting mechanism. From the data provided by an input speed sensor, an output speed sensor, a shift lever position detector and a throttle position sensor, the gears to be shifted are determined. Switching to other gears is done by solenoids. In the fault detection is first waited for a predetermined period of time after changing the switching state of the solenoid. Then it is determined whether the forward gear is set. Subsequently, the calculated gear ratio including the gear stage and the output speed is set and compared with the input shaft speed. This determines whether the actual gear ratio matches the calculated gear ratio. In a mismatch of the calculated gear ratio with the actual gear ratio, an emergency mode is set or an alarm device activated.

Of the Invention is based on the object, a generic vehicle automatic transmission so to improve that it with a simple structure a trouble-free Ensures operation.

These The object is achieved by the characterizing part of the claim 1 specified characteristics solved.

According to the invention is a Error detection device provided, the occurrence of a Error of a hydraulic switching device and the fault detection start determining means, a hydraulic switching means checking means and a hydraulic shifter abnormality determination device, the dependent of whether the hydraulic pressure in response to the engagement command signal to a corresponding other switching element relevant to the current one Gear is not engaged, determines whether the hydraulic switching device has an abnormal condition. This will be fast and detected an error in the hydraulic switching device.

further developments The invention are specified in the subclaims.

The The invention will be explained in more detail with reference to the drawings. Show:

1 12 is a schematic circuit diagram of a transmission assembly in a vehicular automatic transmission in which an error detecting apparatus in a preferred embodiment of the present invention can be applied;

2 a logical table of connections for each gear in an R (reverse) range and a D (forward) range of the drive automatic transmission to which the error detection apparatus of the present invention can be applied;

3 the structure of the hydraulic control system of the vehicular automatic transmission to which the failure detecting apparatus of the present invention can be applied;

4A a schematic circuit block diagram of an electronic control system in the hydraulic control system of 3 .

4B a schematic circuit block diagram of an automatic transmission control unit in the electronic control system of 4A .

5 FIG. 10 is an operational flowchart representing an error detection procedure used in the automatic transmission control unit of FIG 4A and 4B is performed,

6 a logical table indicating whether a slow / reverse brake solenoid valve, described in the preferred embodiment and in 3 shown is powered or not,

7 a characteristic diagram indicating the amount and the duration of the output hydraulic pressure in the preferred embodiment, and

8th a logical table indicating whether or not a 2-4 brake solenoid valve described in the preferred embodiment is energized or not.

in the Referring now to the drawings, the present To illustrate the invention.

1 shows an exemplary transmission arrangement of a vehicle automatic transmission, in which a hydraulic control device of a preferred embodiment of the present invention can be applied.

In 1 If E indicates an engine output axis, I indicates a transmission input axis, and O indicates a transmission output axis. A torque converter T / C is disposed between the engine output axis E and the transmission input axis I. A first planetary gear group G1 and a second planetary gear group G2 are arranged between the input and output axes I and O of the automatic transmission.

The first planetary gear group G1 is a simple planetary gear group with a first pinion P1, a first carrier C1, a first sun gear S1 and a first ring gear R1, and the second planetary gear group G2 is a simple planetary gear group with a second pinion P2, a second carrier C2, a second sun gear S2 and a second ring gear R2.

The Transmission input axis I and the second sun gear S2 are direct coupled. A reverse clutch R / C is mounted at a middle position over a link that the transmission input axis I connects to the first sun gear S1.

A 2-4 brake 2-4 / B with a lamellae structure is attached in such a way that this member on the case can be attached. A quick hitch H / C is at a middle Position over a member attached to the transmission input axis I with the first carrier C1 connects. A low clutch L / C is at a middle position above Link attached, the first carrier C1 with the second ring gear R2 connects. A slow / reverse brake L & R / B with one Lamellar assembly is mounted so that this member attached to the housing can be. A one-way clutch OWC is disposed in parallel with the slow / reverse brake L & R / B. The first ring gear R1 and the second carrier C2 are directly connected to each other coupled. The transmission output axis O is connected to the second carrier C2.

2 Fig. 15 shows a link logic table for each gear in a reverse range (also referred to as R range) and in a forward range (also referred to as D range).

there Note that an ellipse indicates the connected state and a cross the solved State indicates.

in the R-gear are the reverse clutch R / C and the slow / reverse brake L & R / B together connected.

The Slow clutch L / C is connected in first gear of the D range.

in the second gear of the D range are the slow clutch L / C and the 2-4 brake 2-4 / B connected.

in the third gear of the D-range are the low clutch L / C and the Quick coupling H / C connected.

In the fourth gear of the D range, the quick coupling H / C and the 2-4 brake 2-4 / B ge couples. It should be noted that in the first gear (the engine brake is activated in first gear) in a HALTE mode of a slow range (hereinafter L range), the low clutch L / C and the low / reverse clutch L & R / B are connected.

3 shows a transmission control system of the vehicle automatic transmission, in which the hydraulic control device of the present invention can be applied.

In 3 gives the reference number 1 indicates a line pressure hydraulic passage, the reference numeral 2 a manual valve, is the reference numeral 3 indicates a D-range hydraulic pressure passage and indicates the reference numeral 4 an R-range pressure hydraulic passage.

The manual valve 2 is a valve that is in accordance with a selection operation in the D range in which a line pressure oil passage 1 and the D-range pressure oil passage 3 can be connected or switched to the R range, in which the line pressure oil passage 1 and the R-range pressure oil passage 4 are connected.

There are also in 3 the reference number 5 a switching valve and is the reference numeral 6 a switching pressure oil passage.

The switching valve 5 It serves to set the pressure above the line pressure of the line pressure oil passage 1 to reduce to a constant switching pressure.

There are also in 3 shown reference number 7 an operating ratio control low clutch solenoid valve which controls a pressure on a low clutch boost valve 8th applies a slow clutch pressure from a D range pressure in a low clutch boost valve 8th generated and via a low clutch pressure oil pressure passage 9 leads to the slow clutch.

The reference number 10 indicates a duty ratio control quick release solenoid valve. The duty ratio control quick release solenoid valve 10 gives a control pressure for a quick-connect booster valve 11 out. Then, the quick-connect booster valve generates 11 the slow clutch pressure from the D range pressure on the low clutch boost valve 8th and guides the low-clutch pressure via the low-clutch-pressure oil passage 9 to the low clutch L / C. A quick coupling oil pressure switch 13 is at the quick coupling oil pressure passage 12 appropriate. When the hydraulic pressure is applied to the quick coupling, the hydraulic pressure is simultaneously applied to a quick release hydraulic switch 13 applied to the switch 13 ON to turn ON.

The reference number 14 indicates a duty ratio control 2-4 brake solenoid valve. The control pressure is at a 2-4 brake solenoid valve 15 created. A 2-4 brake pressure is applied in the 2-4 brake booster valve 15 generated from the D-range pressure PD and the 2-4 brake-pressure oil passage 16 led to the 2-4 brake 2-4 / B. A 2-4 brake oil pressure switch 17 is at the 2-4 brake pressure oil passage 16 appropriate. When the hydraulic pressure is applied to the 2-4 brake, the hydraulic pressure simultaneously becomes at the 2-4 brake hydraulic switch 17 applied to turn this ON (1> ON).

A slow / reverse brake solenoid valve 18 sets the control pressure for the slow / reverse brake booster valve 19 at. The slow / reverse brake pressure is generated from the line pressure and the slow / reverse brake pressure oil passage 20 led to the slow / reverse brake L & R / B.

A pressure control solenoid valve 22 of the ON / OFF type switches the line pressure to the two stages of high or low pressure.

A duty lock solenoid valve 23 serves to control the connection and solution of the lock-up clutch.

An automatic transmission control unit (ATCU) 24 performs various control operations including gear shift control based on the input information and outputs a solenoid valve control current for each solenoid valve 7 . 10 . 14 . 18 . 22 and 23 in accordance with the processing result.

There is also a first 2-4 brake fail-safe valve 25 a hydraulic valve for which a fuel pressure PFP always applied to one end of a spool (a hydraulic pressure having the same value as a maximum pressure of a quick clutch H / C connected in the D range rapid mode) and a low clutch pressure L / CP acting on the abuts the other end of the coil, serve as operation signal pressures. A second 2-4 brake fail-safe valve 26 is a hydraulic valve for which the fuel pressure PFP applied to one end of the spool and the quick-coupling pressure PH / C applied to the other end of the spool serve as the operation signal pressures.

In a third gear of the D range, in which the low clutch and the quick clutch pressures are generated simultaneously, the Quick-release pressure on the second 2-4 brake fail-safe valve 26 applied so that the slow clutch pressure on the first 2-4 brake fail-safe valve 25 is created. Thus, because the D-range pressure is released, the release of the 2-4 brake pressure is forced.

In 3 gives the reference number 27 a first slow / reverse brake fail-safe valve and is the reference numeral 28 a second slow / reverse brake fail-safe valve. Both in the first slow / reverse brake fail-safe valve 27 as with the second slow / reverse brake fail-safe valve 28 serve the fuel pressure PFP, which is always applied to one end of the coil, and either the quick-coupling pressure PH / C or the 2-4 brake pressure P2-4B as operation signal pressures. In addition, the first and second L / R brake fail-safe valves force 27 and 28 releasing a line pressure so as to release the slow / reverse brake pressure in the second, third and fourth speeds of the D range in which the quick-connect pressure PH / C and / or the 2-4 brake pressure P2-4 / B is generated so that the L / R brake pressure is released.

4A Fig. 10 is a schematic circuit block diagram showing an electronic control system of the hydraulic control operation for the automatic transmission in the preferred embodiment of the present invention.

An engine control unit 29 transmits a throttle opening angle TH and an engine speed Ne serially to an automatic transmission control unit (ATCU) 24 , It should be noted that a torque reduction communication between the engine control unit 29 and the ATCU automatic transmission control unit 24 is made. A turbine speed Nt and an output axle speed No from a turbine speed sensor 30 and an output axis velocity sensor 38 in a power transmission mechanism P / T are placed in the automatic transmission control unit (ATCU) 24 entered.

One in the automatic transmission of 1 installed blocking switch 31 gives a gear to the ATCU 24 out, and one in the automatic transmission of 1 installed hold switch 32 gives a hold switch signal to the ATCU 24 out. A quick-release hydraulic switch 13 , a 2-4 brake hydraulic switch 17 and a slow / reverse brake switch 21 , which are respectively provided in a control valve unit, give switching signals representing hydraulic pressure states at respective switching elements to the ATCU 24 out. An oil temperature signal is from an oil temperature sensor 36 entered.

A solenoid valve control current is provided by the ATCU 24 to each of the solenoid valves 7 . 10 . 14 . 18 . 22 and 23 and a speed indication signal becomes a tachometer 37 issued, which is provided on an instrument panel.

4B shows an internal circuit diagram of the ATCU (automatic transmission control unit) 24 ,

As in 4B shown includes the ATCU 24 : a microprocessor (MPU) 24a , a clock interrupt control unit 24b , a ram 24c , a ROM 24d , an input terminal 24e , an output terminal 24f , one in the input connection 24e contained input communication control unit and one in the output terminal 24f included output communication control unit.

in the Next, the operation of the hydraulic control device in the preferred embodiment described.

5 FIG. 15 is an operational flowchart of the failure detection processing of the hydraulic control device in the preferred embodiment. FIG.

In step 101 determines the ATCU 24 the current gear in accordance with the vehicle speed, the throttle opening angle TH and the selection position information (the area).

In step 102 determines the ATCU 24 Whether the automatic transmission changes to a gear shift position or an operation for selecting the gear range is performed.

When in step 102 with Yes, the routine is terminated.

When in step 102 is decided with no, the routine goes to step 103 ,

In step 103 determines the ATCU 24 whether the gear has been switched to a predetermined gear immediately before.

When in step 103 is decided with no, the routine is terminated.

When in step 103 is decided with Yes, the routine goes from step 103 to step 104 ,

In step 104 determines the ATCU 24 whether the current gear is a forward gear.

When in step 104 is decided with no, the routine is terminated.

When in step 104 is decided with yes, the routine goes to step 105 ,

In step 105 determines the ATCU 24 Whether the vehicle speed V is equal to or higher than a predetermined vehicle speed Vpre.

When in step 105 V <Vpre is (No), the routine is terminated.

When in step 105 V ≥ Vpre is (Yes), the routine goes to step 106 ,

In step 106 determines the ATCU 24 Whether the current oil temperature T is equal to or higher than a predetermined oil temperature Tpre.

When in step 106 T <Tpre is (No), the routine is ended.

In one step 107 , gives the ATCU 24 a connection signal (a power supply for the corresponding solenoid valve (an intermediate value)) to one of the non-connectable clutches from a solenoid valve output table when a failure in one of the fail-safe valves is detected.

In step 108 determines the ATCU 24 whether the hydraulic switch is switched on by one of the unconnected couplings.

When in step 108 If the hydraulic switch is not turned on (No), the routine goes to step 111 ,

When in step 108 When the hydraulic switch is turned on (Yes), the routine goes to step 109 ,

In step 109 determines the ATCU 24 whether a predetermined period of time has elapsed from the time when the hydraulic switch was turned on by one of the clutches not to be connected. When in step 109 is decided with no, the routine goes to step 112 , When in step 109 Yes, the routine goes to step 110 ,

In step 110 an error counter is incremented by one {(error counter) + 1} because the conditions in the steps 108 and 109 be fulfilled.

In step 111 the content of the error counter is cleared to zero because the ON condition of the hydraulic switch in step 108 is not fulfilled.

Then the ATCU determines 24 in step 112 Whether the number in the error counter is equal to or greater than a predetermined number Tipre.

When in step 112 the error counter ≥ Tipre is (Yes), the routine goes to step 113 , When in step 112 the error counter <Tipre is (No), the routine goes to step 114 ,

In step 113 determines the ATCU 24 in that the fail-safe valve has failed, and the routine goes to step 115 ,

In step 114 , determines the ATCU 24 in that the fail-safe valve is operated normally.

In step 115 warns the ATCU 24 the vehicle occupant on the occurrence of a fault in the fail-safe valve.

The following describes the case that the above-described error detection processing is based on a failure determination for the first slow / reverse brake fail-safe valve 27 and the second slow / reverse brake fail-safe valve 28 is applied.

The gear step becomes as with respect to the step 101 from 5 described in accordance with the vehicle speed V, the opening angle of the throttle valve TH and the selection position information determined to ensure that the automatic transmission is not currently performing a gearshift operation or a gear range selection operation.

This Determination process is carried out because the hydraulic pressure during a gearshift operation or a selection operation unstable is, so that the determination of an abnormality is difficult.

in the the following will be explained why is it ensured that immediately before the gear to a predetermined Gear in the forward area (in this case the second, third or fourth gear) has been.

If namely the 2-4 brake 2-4 / B and the slow / reverse brake L & R / B simultaneously connected or the quick release and the slow / reverse brake are connected at the same time, the blocking phenomenon occurs.

To prevent this lockup, when the 2-4 brake pressure or the quick-coupling pressure is generated, the first and second slow / reverse brake fail-safe valves become 27 and 28 operated to force a release of the slow / reverse brake pressure. In other words, when the gear is the second, third, or fourth gear, the slow / reverse solenoid valve becomes 18 operated to connect the slow / reverse brake. If the fail-safe valve 27 or 28 However, when working normally, the slow / reverse However, the brake is not connected.

When the condition described above is satisfied, as in 6 shown a connection command signal to the slow / reverse brake solenoid valve 18 issued when the gear is the second, third or fourth gear.

7 shows the height and duration of the hydraulic pressure.

In 7 the horizontal axis represents the time, while the vertical axis represents the hydraulic pressure. When the solenoid valve OFF output is output, it indicates the degree of hydraulic pressure generated using the normal hydraulic pressure. So if in the second, third or fourth gear, the first and second slow / reverse brake fail-safe valve 27 and 28 operating normally, the hydraulic pressure is not applied to the slow / reverse brake L & R / B.

In 7 indicates the hydraulic pressure when no hydraulic switch is turned on, and indicates the hydraulic pressure when the hydraulic switch is always turned on.

It should be noted that the output hydraulic pressure when the slow / reverse brake hydraulic switch 21 is on, slightly less than a minimum pressure required to connect the slow / reverse brake. Even if the hydraulic pressure were generated, the hydraulic pressure is so weak that the clutch grinds and no lock occurs, so that the error can be detected.

There are also c in 7 a period of time longer than a vibration period (a period of time that allows elimination of an influence of oil vibration due to occurrence during the duty ratio period) while d in 7 indicates a ramp pressure, e indicates a time delay period, and f indicates a time limit for a ramp time.

there it should be noted that the time limit f for the ramp time is used to prevent an infinite loop of the hydraulic control in case the slope of the ramp pressure is low.

If the hydraulic pressure b is not reached even after the time f, the transmission of the area c forced as hydraulic pressure b.

In the above-described state c, when the slow / reverse brake hydraulic switch 21 from OFF state to ON state changes (OFF → ON) and the ON state of the switch 21 continuously for 30 milliseconds, an abnormal condition is determined once. If an abnormal condition is detected twice, the ATCU determines 24 an error in the fail-safe valve. The ATCU 24 then warns the vehicle occupants.

The continuous and double fault detection for the determination the abnormal function of the fail-safe valve is to to prevent a wrong determination.

If continue the automatic transmission control unit 24 during the period c determines that the slow / reverse hydraulic switch 21 from the ON state to the OFF state, the ATCU gives 24 the command to increment the error counter by one not to prevent an incorrect determination.

Of course it will the fault detection processing stopped when a gear shift or a selection control during the implementation of a such processing as described above, with the other controller assigned a higher priority becomes.

If the gear remains the same, the fail-safe valves do not remain spontaneously stuck in the opposite direction. It is not required, the error detection processing often with irregular time intervals perform.

The specific fault detection for each of the two slow / reverse brake fail-safe valves 27 and 28 will be described with reference to the flowchart of 5 explained.

Because in the third gear, the 2-4 brake pressure P2-4 / B is not applied, but the quick-coupling pressure PH / C at the first slow / reverse brake fail-safe valve 27 is applied, the line pressure is released. In this stage, the slow / reverse solenoid valve 18 powered. This power supply quantity corresponds to a pressure, so that the above-described corresponding slow / reverse brake hydraulic switch is turned on. When the slow / reverse brake hydraulic switch 21 is turned on, determines the automatic transmission control unit 24 an error of the first slow / reverse fail-safe valve 27 and warns the vehicle occupants.

Accordingly, because the quick-coupling pressure PH / C is not applied in the second speed, but the 2-4 brake pressure P2-4 / B is applied to the above-described corresponding second brake-failure-limiting valve 28 is applied, the line pressure is released. At this stage, that will 2-4 brake solenoid valve 14 as in 4 Powered and becomes the 2-4 brake hydraulic switch 17 switched from OFF state to ON state (OFF → ON), allowing the automatic transmission control unit 24 the occurrence of a fault in the second slow / reverse brake fail-safe valve 28 determines and warns the vehicle occupants.

The following describes the case that described above and in 5 shown processing on the fault determination for the first and second 2-4 brake fail-safe valve 25 and 26 is applied.

Here, the underlying processing flow is the same as above with respect to the first and second slow / reverse brake fail-safe valves 27 and 28 described. Therefore, here are just the differences compared to the finding for the valves 27 and 28 described.

in the The following describes why it is ensured that the Automatic transmission immediately before in the predetermined forward gear (in this case in the third gear) is switched.

If the 2-4 brake is actuated is, the quick release and the low clutch are simultaneously connected, so the blocking phenomenon occurs.

To prevent this lock, when the quick-coupling pressure PH / C and the low-clutch pressure PL / C are simultaneously generated, the first and second 2-4 brake fail-safe valves are forced 25 and 26 releasing the 2-4 brake pressure.

When the gear is in third gear, the 2-4 brake solenoid valve becomes 14 actuated. Even if an attempt is made to connect the 2-4 brake, the 2-4 brake will become the normal function of the fail-safe valves 25 and 26 not connected.

When the condition described above is satisfied, the connection command signal becomes as in 8th shown in third gear to the 2-4 brake solenoid valve 14 output.

The following is the specific fault detection for the 2-4 brake fail-safe valves 25 and 26 with reference to the flow chart of 5 described.

In third gear, the 2-4 brake pressure P2-4 / B is not applied, but the quick-coupling pressure PH / C is applied so that the low-clutch pressure PL / C on the first 2-4 brake failsafe valve 25 is created. Applying the slow clutch pressure PL / C causes the D range pressure to be released at the first 2-4 brake failsafe valve.

This will be the 2-4 brake solenoid valve 14 powered. The power supply quantity corresponds to a pressure sufficient to the above-described corresponding hydraulic switch (the 2-4-brake hydraulic switch 17 ).

When the 2-4 brake hydraulic switch 17 is turned on, determines the automatic transmission control unit 24 in that either the first or the second 2-4 brake failsafe valve 25 or 26 failed, and warns the vehicle occupants.

In accordance with the fault detection for the fail-safe valves described above, the automatic transmission control unit monitors 24 always, whether the fail-safe valves are operated without errors, to produce the lock even if the windings of the solenoid valves are broken.

One not on conventional Way detectable error can not be determined. Continue the occurrence of a fault informed the vehicle occupant. The frequency The lock can be reduced by the occurrence of another error a failover for a double error is provided. This can be the safety standard elevated become.

It It should be noted that in the preferred embodiment described above two valves are provided as fail-safe valves, wherein but also a single valve or three or more valves as Fail-safe valves can be provided.

The entire contents of the Japanese Patent Application No. Heisei 11-223337 (filed on Aug. 6, 1999 in Japan) is hereby incorporated by reference.

Claims (16)

A vehicle automatic transmission having: a plurality of shift elements (L / C, 2-4 / B, H / C, L & R / B, R / C) a gear shift mechanism in which combinations of engagement states of the respective shift elements (L / C, 2) 4 / B, H / C, L & R / B, R / C) by means of a hydraulic control section ( 24 ) are selected to perform a shift between multiple gears, and a hydraulic switching device ( 25 - 28 ) located in the hydraulic control area ( 24 ) is provided to lock the gearshift mechanism to prevent, characterized by an error detection device ( 101 - 113 ) indicating the occurrence of a failure of the hydraulic switching device ( 25 - 28 ), wherein the error detection device ( 101 - 113 ) comprises: a gear determination device ( 101 ) to determine the current gear of the automatic transmission, an error detection start determining device ( 102 - 106 ), the beginning of the fault detection of the hydraulic switching device ( 25 - 28 ) in accordance with the determination result of the gear determination device (FIG. 101 ), a memory for storing the switching elements selected for the combinations of engagement states for the respective gears and the shift elements not selected for the respective gears in the form of a table, a hydraulic shift device tester (Fig. 107 ) for outputting an engagement command signal to instruct the engagement of each other shift element not to be engaged with the current gear and read out from the memory, and a hydraulic shift abnormality determination means (Fig. 108 - 113 ) via the test facility ( 107 ), depending on whether the hydraulic pressure remains in response to the engagement command signal to the corresponding other switching element, determines whether the hydraulic switching device ( 25 - 28 ) has an abnormal condition. A vehicle automatic transmission according to claim 1, characterized in that said hydraulic shift abnormality determining means (14) 108 - 113 ) the state of the hydraulic switching device ( 25 - 28 ) in accordance with the state of a hydraulic switch ( 17 ; 21 ) in a hydraulic circuit of the hydraulic control section ( 24 ) is provided and connected to the corresponding other non-engageable switching element. Vehicle automatic transmission according to claim 2, characterized characterized in that the hydraulic switch is turned on under the condition is that the hydraulic pressure in the hydraulic circuit by a predetermined Pressure higher is considered a minimum pressure for the corresponding other not to be connected switching element required is, but lower than the corresponding maximum pressure. A vehicle automatic transmission according to any one of claims 1 to 3, characterized in that the fault detection start determining device ( 102 - 106 ) prevents the start of the hydraulic device fault detection while the automatic transmission performs a gear shift operation or a gear range selection operation. A vehicle automatic transmission according to one of claims 1 to 4, characterized in that the fault detection start determination device ( 102 - 106 ) determined only with the error detection for the hydraulic switching device ( 25 - 28 ) to start when the current gear is a predetermined gear. A vehicle automatic transmission according to one of claims 1 to 5, characterized in that the fault detection start determination device ( 102 - 106 ) determined only with the error detection for the hydraulic switching device ( 25 - 28 ) when the oil temperature (T) is equal to or higher than a predetermined oil temperature (T _pre ). Automatic vehicle transmission according to one of Claims 1 to 6, characterized in that the fault detection start determination device ( 102 - 106 ) determined only with the error detection for the hydraulic switching device ( 25 - 28 ) when the vehicle speed (V) is equal to or higher than a predetermined vehicle speed (V _pre ). A vehicle automatic transmission according to one of claims 1 to 7, characterized in that the fault detection start determination device ( 102 - 106 ) determined only with the error detection for the hydraulic switching device ( 25 - 28 ) to start when the current gear is a forward gear. A vehicle automatic transmission according to any one of claims 1 to 8, characterized in that the fault detection device ( 101 - 113 ) the current error detection for the hydraulic switching device ( 25 - 28 ) stops when a gear shift operation or a gear range selection operation during the failure detection for the hydraulic shift device (FIG. 25 - 28 ) be performed. Vehicle automatic transmission according to one of claims 1 to 9, characterized in that the hydraulic switching device ( 25 - 28 ) is a hydraulic switching valve and the abnormality determining means ( 108 - 113 ) determines that the hydraulic switching valve is in the abnormal state when the abnormality determining means ( 108 - 113 ) certain abnormal state of the hydraulic switching valve continues for a predetermined period of time. Automatic vehicle transmission according to one of claims 1 to 10, characterized in that the abnormality determination device ( 108 - 113 ) an error counter ( 110 ), which is incremented by one each time the abnormality is determined device ( 108 - 113 ) determines that the abnormal state of the hydraulic switching device ( 25 - 28 ) continuously for the predetermined period of time, the abnormality determination means ( 108 - 113 ) determines that the hydraulic switching device ( 25 - 28 ) is in the abnormal state when a count value of the error counter ( 110 ) reaches a predetermined count. A vehicle automatic transmission according to any one of claims 1 to 11, characterized in that when the abnormality determination means ( 108 - 113 ) determines that the hydraulic switching device ( 25 - 28 ) is in a normal state before the count of the error counter ( 110 ) reaches the predetermined count, the count of the error counter ( 110 ) is deleted. Vehicle automatic transmission according to one of Claims 1 to 12, characterized by a warning device ( 115 ), which informs the vehicle occupant of the vehicle through the abnormality determination device ( 108 - 113 ) detected abnormal state of the hydraulic switching device ( 25 - 28 ). A vehicular automatic transmission according to any one of claims 2 to 13, characterized in that one of the other non-engaging shift elements is a slow / reverse brake (L & R / B) when the current gear is either the second or third gear Hydraulic switch a slow / reverse brake hydraulic switch ( 21 ) and the test device is the intervention command signal to a slow / reverse brake solenoid valve ( 18 ), wherein the hydraulic switching device has a first slow / reverse fail-safe valve ( 27 ) is when the current gear is the third gear. A vehicular automatic transmission according to any one of claims 2 to 14, characterized in that one of the other non-engaging shift elements is a slow / reverse brake (L & R / B) when the current gear is either the second or third gear, the hydraulic switch a 2-4 brake hydraulic switch ( 17 ) and the test device sends the intervention command signal to a 2-4 brake solenoid valve ( 14 ), wherein the hydraulic switching device has a second slow / reverse fail-safe valve ( 28 ) is when the current gear is the second gear. A vehicular automatic transmission according to any one of claims 2 to 15, characterized in that one of the other non-engaging shift elements is a 2-4 brake (2-4 / B) when the current gear is the third gear Hydraulic switch a 2-4 brake hydraulic switch ( 17 ) and the tester sends the engagement command signal to a 2-4 brake solenoid valve ( 14 ), wherein the hydraulic switching device is a first or second 2-4-fail-safe valve ( 25 . 26 ) is when the current gear is the third gear.